Battery School

Cycle the battery lightly (20% or less depth of discharge) the first
few cycles. This helps complete the forming process of the plates (in
case they are not completely finished forming).

Always allow batteries to "cool off" after charging. The cooling
time is very important because heat is generated during the recharge and discharge
cycles. Without the cooling time the heat grows, accelerating grid corrosion,
which is one of the major causes of battery failure.

Opportunity charging (quick charging between uses) is detrimental to
battery life. While it is true that the shallower the cycle, the more
cycles the battery can deliver, opportunity charging is not good because the
cooling time is eliminated, shortening life. (I.e. One charge cycle per day
is preferable.)

Never charge a wet battery with a sealed (gel cell) battery charger.The
wet battery needs the higher voltages to finish the charge and without it
the batteries never come back to 100% and sulfation can occur.

Never let the electrolyte level of a wet battery fall below
the plates. Lack of maintaining the electrolyte in a wet battery causes
damage (sulfation) to the exposed portion of the plate that reduces capacity.

Never store a battery in a discharged state. The sulfate that forms
during discharge should not be ignored for an extended time period because
severe sulfation will take place sometimes, making the battery impossible
to recharge fully.

Always fill your serviceable, wet batteries with water (preferably distilled)
after they have been charged). If the electrolyte level is at least above
the plates, do not fill the battery until after recharge. The electrolyte
expands during charging and if you fill them before recharging, the electrolyte
will possibly bubble out of the battery. The plates must be covered with electrolyte
for recharge but be careful not to overfill.

Always keep the tops and terminals of batteries clean and free of corrosion.
The film on top of the battery can cause the current to migrate between the
posts, accelerating self-discharge.

A fully charged battery will give you the best and longest service. Be
sure the batteries are fully charged before testing or using your R..Vs.
A fully charged battery, without a drain or load, after the surface charge
has dissipated, is 12.63 volts for a 12 volt battery. Other states of charge
are: 12.60 volts = 93% charged 12.55 volts = 89% charged 12.50 volts = 85%
charged 12.45 volts = 80 % charged 12.18 volts = 50 % charged.

An overly discharged battery may need to be cycled a few times before
it can recover fully. If a battery begins to heat before coming up to
a full state of charge, it may be necessary to discharge the battery and recharge
it a few times. This charge and discharge cycle may help the current acceptance
of the battery and facilitate its recovery to a usable condition.

In situations where multiple batteries are connected in parallel, series
or series/parallel, a replacement battery(s) should be of the same size, age
and usage level as the companion batteries. Do not put a new battery in
a pack that has 50 or more cycles. Either replace with all new or use a good
used battery(s).

Deepcycle batteries need to be equalized periodically. Equalizing
is an extended, low current charge performed after the normal charge cycle.
It helps keeps cells in balance. Actively used batteries should be equalized
once per week. Manually timed chargers should have the charge time extended
about 3 hours. Automatically controlled chargers should be unplugged and reconnected
after completing a charge cycle.

As batteries age, their maintenance requirements change. Generally
their specific gravity is higher. Gassing voltage goes up. This means longer
charging time and/or higher finish rate (higher amperage at the end of charge).
Usually, older batteries need to be watered more often. And, their capacity
decreases.

Inactivity can be harmful to deep cycle batteries. If they sit for
several months, a "boost" charge should be given; more frequently in warm
climate (about once a month) than in cold (every 2-3 months). This is because
batteries discharge faster at higher temperatures than at colder temperatures.